Use bucket DB read guards for metric and status aggregation

4 files changed, 34 insertions, 17 deletions

diff --git a/storage/src/tests/bucketdb/lockablemaptest.cpp b/storage/src/tests/bucketdb/lockablemaptest.cpp
index c0d29aad158..709e158e531 100644
--- a/storage/src/tests/bucketdb/lockablemaptest.cpp
+++ b/storage/src/tests/bucketdb/lockablemaptest.cpp
@@ -356,6 +356,22 @@ TYPED_TEST(LockableMapTest, can_abort_during_chunked_iteration) {
     EXPECT_EQ(expected, proc.toString());
 }
 
+TYPED_TEST(LockableMapTest, can_iterate_via_read_guard) {
+    TypeParam map;
+    bool pre_existed;
+    map.insert(16, A(1, 2, 3), "foo", pre_existed);
+    map.insert(11, A(4, 6, 0), "foo", pre_existed);
+    map.insert(14, A(42, 0, 0), "foo", pre_existed);
+    std::string expected("11 - A(4, 6, 0)\n"
+                         "14 - A(42, 0, 0)\n"
+                         "16 - A(1, 2, 3)\n");
+
+    ConstProcessor<TypeParam> cproc;
+    auto guard = map.acquire_read_guard();
+    guard->for_each(std::ref(cproc));
+    EXPECT_EQ(expected, cproc.toString());
+}
+
 TYPED_TEST(LockableMapTest, find_buckets_simple) {
     TypeParam map;
 
diff --git a/storage/src/vespa/storage/bucketdb/bucketmanager.cpp b/storage/src/vespa/storage/bucketdb/bucketmanager.cpp
index fcb019fb6bc..530c1236436 100644
--- a/storage/src/vespa/storage/bucketdb/bucketmanager.cpp
+++ b/storage/src/vespa/storage/bucketdb/bucketmanager.cpp
@@ -174,12 +174,11 @@ namespace {
         std::vector<Count> disk;
         uint32_t lowestUsedBit;
 
-        MetricsUpdater(uint16_t diskCnt)
+        explicit MetricsUpdater(uint16_t diskCnt)
             : diskCount(diskCnt), disk(diskCnt), lowestUsedBit(58) {}
 
-        StorBucketDatabase::Decision operator()(
-                document::BucketId::Type bucketId,
-                const StorBucketDatabase::Entry& data)
+        void operator()(document::BucketId::Type bucketId,
+                        const StorBucketDatabase::Entry& data)
         {
             document::BucketId bucket(
                     document::BucketId::keyToBucketId(bucketId));
@@ -200,8 +199,6 @@ namespace {
                     lowestUsedBit = bucket.getUsedBits();
                 }
             }
-
-            return StorBucketDatabase::Decision::CONTINUE;
         };
 
         void add(const MetricsUpdater& rhs) {
@@ -241,7 +238,8 @@ BucketManager::updateMetrics(bool updateDocCount)
         MetricsUpdater total(diskCount);
         for (auto& space : _component.getBucketSpaceRepo()) {
             MetricsUpdater m(diskCount);
-            space.second->bucketDatabase().for_each_chunked(std::ref(m), "BucketManager::updateMetrics");
+            auto guard = space.second->bucketDatabase().acquire_read_guard();
+            guard->for_each(std::ref(m));
             total.add(m);
             if (updateDocCount) {
                 auto bm = _metrics->bucket_spaces.find(space.first);
@@ -270,8 +268,7 @@ BucketManager::updateMetrics(bool updateDocCount)
 void BucketManager::updateMinUsedBits()
 {
     MetricsUpdater m(_component.getDiskCount());
-    _component.getBucketSpaceRepo().forEachBucketChunked(
-            m, "BucketManager::updateMetrics");
+    _component.getBucketSpaceRepo().for_each_bucket(std::ref(m));
     // When going through to get sizes, we also record min bits
     MinimumUsedBitsTracker& bitTracker(_component.getMinUsedBitsTracker());
     if (bitTracker.getMinUsedBits() != m.lowestUsedBit) {
@@ -339,9 +336,7 @@ namespace {
     public:
         explicit BucketDBDumper(vespalib::XmlOutputStream& xos) : _xos(xos) {}
 
-        StorBucketDatabase::Decision operator()(
-                uint64_t bucketId, const StorBucketDatabase::Entry& info)
-        {
+        void operator()(uint64_t bucketId, const StorBucketDatabase::Entry& info) {
             using namespace vespalib::xml;
             document::BucketId bucket(
                     document::BucketId::keyToBucketId(bucketId));
@@ -355,7 +350,6 @@ namespace {
             info.getBucketInfo().printXml(_xos);
             _xos << XmlAttribute("disk", info.disk);
             _xos << XmlEndTag();
-            return StorBucketDatabase::Decision::CONTINUE;
         };
     };
 }
@@ -377,8 +371,8 @@ BucketManager::reportStatus(std::ostream& out,
             xmlReporter << XmlTag("bucket-space")
                         << XmlAttribute("name", document::FixedBucketSpaces::to_string(space.first));
             BucketDBDumper dumper(xmlReporter.getStream());
-            _component.getBucketSpaceRepo().get(space.first).bucketDatabase().for_each_chunked(
-                    std::ref(dumper), "BucketManager::reportStatus");
+            auto guard = _component.getBucketSpaceRepo().get(space.first).bucketDatabase().acquire_read_guard();
+            guard->for_each(std::ref(dumper));
             xmlReporter << XmlEndTag();
         }
         xmlReporter << XmlEndTag();
@@ -398,7 +392,7 @@ BucketManager::dump(std::ostream& out) const
 {
     vespalib::XmlOutputStream xos(out);
     BucketDBDumper dumper(xos);
-    _component.getBucketSpaceRepo().forEachBucketChunked(dumper, "BucketManager::dump");
+    _component.getBucketSpaceRepo().for_each_bucket(std::ref(dumper));
 }
 
 
diff --git a/storage/src/vespa/storage/bucketdb/storbucketdb.cpp b/storage/src/vespa/storage/bucketdb/storbucketdb.cpp
index 6940c072ed6..849164ace7d 100644
--- a/storage/src/vespa/storage/bucketdb/storbucketdb.cpp
+++ b/storage/src/vespa/storage/bucketdb/storbucketdb.cpp
@@ -138,7 +138,7 @@ void StorBucketDatabase::for_each(
 
 std::unique_ptr<bucketdb::ReadGuard<StorBucketDatabase::Entry>>
 StorBucketDatabase::acquire_read_guard() const {
-    return {};
+    return _impl->acquire_read_guard();
 }
 
 template class JudyMultiMap<bucketdb::StorageBucketInfo>;
diff --git a/storage/src/vespa/storage/common/content_bucket_space_repo.h b/storage/src/vespa/storage/common/content_bucket_space_repo.h
index 142bb5ea1d5..6d8bd67b071 100644
--- a/storage/src/vespa/storage/common/content_bucket_space_repo.h
+++ b/storage/src/vespa/storage/common/content_bucket_space_repo.h
@@ -43,6 +43,13 @@ public:
         }
     }
 
+    template <typename Functor>
+    void for_each_bucket(Functor functor) const {
+        for (const auto& elem : _map) {
+            elem.second->bucketDatabase().acquire_read_guard()->for_each(std::move(functor));
+        }
+    }
+
 };
 
 }